Cortázar's short stories are great examples of "hijacked" realist fiction. Both "The Continuity of Parks" and "House Taken Over" incorporate elements of magical realism that cause us to question reality.
In "The Continuity of Parks," time is fluid (one of the most important elements of magical realism). The man in the green velvet armchair is also the hapless husband the hero has set out to kill. Here, the lines between reality and the irrational have been blurred. We know that one can't possibly read about one's impending murder from a book. Yet Cortázar implies that this is possible. What's more, he describes this possibility in a matter-of-fact way.
The narrator shows no alarm that logic has been hijacked by fanciful surrealism. This is another way Cortázar destroys the conventions of realist fiction. What might be considered metaphor in another fictional story is treated as reality in "The Continuity of Parks." Consider the passage below. It is full of metaphors but menacingly "real" within the context of the story.
The dagger warmed itself against his chest, and underneath pounded liberty, ready to spring. A lustful, yearning dialogue raced down the pages like a rivulet of snakes, and one felt it had all been decided from eternity. Even those caresses which writhed about the lover's body, as though wishing to keep him there, to dissuade him from it, sketched abominably the figure of that other body it was necessary to destroy.
In the passage above, lustful infatuation births evil motives and actions (a yearning lust is compared to a "rivulet of snakes"). This cause-and-effect element then leaps from the pages of a fictionalized world into reality. Meanwhile, Cortázar remains tight-lipped about whether irrationality is successful in subverting reality. The conclusion of the story remains open-ended (will the man in the green chair die?), one of the key elements of magical realism.
In "House Taken Over," the conclusion is also open-ended. Cortázar never reveals the source of the noises or the identity of those who have supposedly "taken over the house." The open-ended uncertainty in both stories is another way Cortázar has destroyed the conventions of realist fiction. Unlike realist fiction, magical realism never explains the fantastical elements in a story; instead, they are treated as a normal, intrinsic part of the plot.
In "House Taken Over," the brother and sister eventually find themselves out on the street. The brother has locked the front door and thrown the key down the sewer. It's a perplexing action, since we don't know what or who has driven the siblings out of their home. Just like in "The Continuity of Parks," Cortázar focuses our attention on the emotions of the protagonists. In magical realism, the plausibility of events takes a back seat to strong sentiment. This is unlike realist fiction, where the author/narrator tries to provide plausible reasons for the actions of characters.